U.S. patent application number 12/687403 was filed with the patent office on 2010-07-15 for method, system and installation for forwarding data transmission frames.
This patent application is currently assigned to TELLABS OY. Invention is credited to Mikko LAULAINEN, Juha-Petteri NIEMINEN, Mika SILVOLA.
Application Number | 20100177702 12/687403 |
Document ID | / |
Family ID | 40329480 |
Filed Date | 2010-07-15 |
United States Patent
Application |
20100177702 |
Kind Code |
A1 |
NIEMINEN; Juha-Petteri ; et
al. |
July 15, 2010 |
METHOD, SYSTEM AND INSTALLATION FOR FORWARDING DATA TRANSMISSION
FRAMES
Abstract
In a system, the functionality is decentralized in a data
transmission network so that the need of communications produced by
and addressed to data terminals to pass by way of a single point in
the data transmission network is diminished. A first data
transmission installation is adapted to signal second data
transmission installations, each of which is part of a ring-shaped
data transmission topology, to be capable of building logical data
transmission tunnels directed to the data terminals. Thereby, all
the logical data transmission tunnels need not commence or,
depending on the direction, terminate at the same point of a data
transmission network. In addition, the data transmission
installations present in a ring-shaped data transmission topology
need not necessarily be taught routing information in order to
enable each of these data transmission installations to send data
transmission frames to be transmitted to another one of these data
transmission installations.
Inventors: |
NIEMINEN; Juha-Petteri;
(Espoo, FI) ; SILVOLA; Mika; (Kempele, FI)
; LAULAINEN; Mikko; (Helsinki, FI) |
Correspondence
Address: |
YOUNG & THOMPSON
209 Madison Street, Suite 500
Alexandria
VA
22314
US
|
Assignee: |
TELLABS OY
Espoo
FI
|
Family ID: |
40329480 |
Appl. No.: |
12/687403 |
Filed: |
January 14, 2010 |
Current U.S.
Class: |
370/328 |
Current CPC
Class: |
H04L 12/42 20130101 |
Class at
Publication: |
370/328 |
International
Class: |
H04W 40/00 20090101
H04W040/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 14, 2009 |
FI |
20095023 |
Claims
1. A data transmission installation for forwarding data
transmission frames, the data transmission installation comprising
data receivers for receiving data transmission frames in the data
transmission installation, data transmitters for sending data
transmission frames from the data transmission installation, and a
processor unit adapted to: read control data from one or more
received data transmission frames, the control data containing
building and cancelling commands for logical data transmission
tunnels determined on the basis of mobility of data terminals
connected to a data transmission network, execute building and
cancelling actions determined by the control data for logical data
transmission tunnels, and determine forwarding actions for a
received second data transmission frame on the basis of forwarding
control data contained in the second data transmission frame, the
forwarding actions comprising a transmission of the second data
transmission frame by way of one of following (i-iii): (i) a
predetermined output port of the data transmission installation or
(ii) one of two optional predetermined output ports of the data
transmission installation or (iii) a logical data transmission
tunnel commencing from the data transmission installation.
2. A data transmission installation according to claim 1, wherein
the processor unit is adapted to read second control data from one
or more received third data transmission frames and to select one
of the two optional predetermined output ports on the basis of the
second control data and forwarding control data contained in the
second data transmission frame.
3. A data transmission installation according to claim 1, wherein
the processor unit is adapted to select one of the optional
predetermined output ports on the basis of forwarding control data
contained in the second data transmission frame and one or more
predefined conditions relevant to the forwarding control data.
4. A data transmission installation according to claim 1, wherein
the processor unit is adapted to read second control data from one
or more received third data transmission frames and to primarily
select one of the two optional predetermined output ports on the
basis of the second control data and forwarding control data
contained in the second data transmission frame, and secondarily,
in response to a situation in which the second control data does
not fulfill predefined criteria, to select one of the two optional
predetermined output ports on the basis of forwarding control data
contained in the second data transmission frame and on the basis of
one or more predefined conditions relevant to the forwarding
control data.
5. A data transmission installation according to claim 1, wherein
the processor unit is adapted to write third control data into one
or more fourth data transmission frames to be sent, which control
data is adapted to indicate one or more data terminals with a
logical data transmission tunnel directed thereto commencing from
the data transmission installation.
6. A data transmission installation according to claim 1, wherein
the processor unit is adapted to support GTP-U (General Packet
Radio Service Tunneling Protocol--User plane messages) data
transmission tunnels.
7. A data transmission installation according to claim 1, wherein
the processor unit is adapted to support GRE (Generic Routing
Encapsulation) data transmission tunnels.
8. A data transmission installation according to claim 1, wherein
the processor unit is adapted to support data transmission tunnels
implemented by means of Ethernet frames.
9. A data transmission installation according to claim 1, wherein
the processor unit is adapted to support IPinIP (Internet Protocol
in Internet Protocol) data transmission tunnels.
10. A data transmission installation according to claim 1, wherein
the data transmission frames are IP (Internet Protocol)
packets.
11. A data transmission installation according to claim 1, wherein
the data transmission frames are Ethernet frames.
12. A data transmission installation according to claim 10, wherein
the processor unit is adapted to use an IP (Internet Protocol)
destination address at least as part of the forwarding control
data.
13. A data transmission installation according to claim 11, wherein
the processor unit is adapted to use an Ethernet destination
address at least as part of the forwarding control data.
14. A data transmission installation according to claim 1, wherein
the processor unit is adapted to select, on the basis of forwarding
control data for the second data transmission frame, one of the
predefined virtual data transmission networks.
15. A data transmission installation according to claim 1, wherein
the predefined virtual data transmission networks are IP VPN
(Internet Protocol, Virtual Private Network) virtual data
transmission networks.
16. A data transmission installation according to claim 1, wherein
the predefined virtual data transmission networks are VPLS (Virtual
Private LAN Service) virtual data transmission networks.
17. A data transmission installation according to claim 1, wherein
the data transmission installation is at least one of the
following: an IP (Internet Protocol) router, an MPLS (Multiprotocol
Label Switching) switch, and an Ethernet switch.
18. A data transmission installation for controlling the forwarding
of data transmission frames, the data transmission installation
comprising: data transmitters for sending data transmission frames
from the data transmission installation, and a processor unit which
is adapted to write control data into one or more first data
transmission frames to be sent to another data transmission
installation, the control data containing building and cancelling
commands for logical data transmission tunnels determined on the
basis of mobility of data terminals connected to a data
transmission network, wherein the processor unit is further adapted
to write second control data into one or more second data
transmission frames to be sent to the other data transmission
installation, the second control data containing location-related
information, which is updated on the basis of the mobility of the
data terminals and which enables selecting for a ring-shaped data
transmission topology a data transfer direction which, according to
a predetermined criterion, is more advantageous for carrying a
third data transmission frame, addressed to one of the data
terminals, to the commencing point of a logical data transmission
tunnel directed to this particular data terminal.
19. A data transmission installation according to claim 18, wherein
the data transmission tunnels are GTP-U (General Packet Radio
Service Tunneling Protocol--User plane messages) data transmission
tunnels.
20. A data transmission installation according to claim 18, wherein
the data transmission tunnels are GRE (Generic Routing
Encapsulation) data transmission tunnels.
21. A data transmission installation according to claim 18, wherein
the data transmission tunnels are data transmission tunnels
implemented by means of Ethernet frames.
22. A data transmission installation according to claim 18, wherein
the data transmission tunnels are IPinIP (Internet Protocol in
Internet Protocol) data transmission tunnels.
23. A data transmission installation according to claim 18, wherein
the data transmission frames are IP (Internet Protocol)
packets.
24. A data transmission installation according to claim 18, wherein
the data transmission frames are Ethernet frames.
25. A data transmission installation according to claim 18, wherein
the data transmission installation is at least one of the
following: an IP (Internet Protocol) router, an MPLS (Multiprotocol
Label Switching) switch, and an Ethernet switch.
26. A method for forwarding data transmission frames, the method
comprising: receiving one or more first data transmission frames in
a data transmission installation, reading control data from the one
or more first data transmission frames, which control data contains
building and cancelling commands for logical data transmission
tunnels determined on the basis of mobility of data terminals
connected to a data transmission network, executing building and
cancelling actions determined by the second control data for
logical data transmission tunnels, determining forwarding actions
for a second received data transmission frame on the basis of
forwarding control data contained in the second data transmission
frame, the forwarding actions comprising a transmission of the
second data transmission frame by way of one of the following
(i-iii): (i) a predetermined output port of the data transmission
installation or (ii) one of two optional predetermined output ports
of the data transmission installation or (iii) a logical data
transmission tunnel commencing from the data transmission
installation, and sending the second transmission frame in
compliance with the determined forwarding actions.
27. A method according to claim 26, wherein the method comprises
reading second control data from one or more received third data
transmission frames and selecting one of the two optional output
ports on the basis of the second control data and forwarding
control data contained in the second data transmission frame.
28. A method according to claim 26, wherein the method comprises
selecting one of the two optional predetermined output ports on the
basis of forwarding control data contained in the second data
transmission frame and on the basis of one or more predefined
conditions relevant to the forwarding control data.
29. A method according to claim 26, wherein the method comprises
reading second control data from one or more third data
transmission frames and primarily selecting one of the two optional
predetermined output ports on the basis of the second control data
and forwarding control data contained in the second data
transmission frame, and secondarily, in response to a situation in
which the second control data does not fulfill predetermined
criteria, selecting one of the optional predetermined output ports
on the basis of forwarding control data contained in the second
data transmission frame and on the basis of one or more predefined
conditions relevant to the forwarding control data.
30. A method according to claim 26, wherein the method comprises
writing third control data into one or more fourth data
transmission frames to be sent, which control data is adapted to
indicate one or more data terminals with a logical data
transmission tunnel directed thereto commencing from the data
transmission installation.
31. A method according to claim 26, wherein the data transmission
tunnels are GTP-U (General Packet Radio Service Tunneling
Protocol--User plane messages) data transmission tunnels.
32. A method according to claim 26, wherein the data transmission
tunnels are GRE (Generic Routing Encapsulation) data transmission
tunnels.
33. A method according to claim 26, wherein the data transmission
tunnels are implemented by means of Ethernet frames.
34. A method according to claim 26, wherein the data transmission
tunnels are IPinIP (Internet Protocol in Internet Protocol) data
transmission tunnels.
35. A method according to claim 26, wherein the data transmission
frames are IP (Internet Protocol) packets.
36. A method according to claim 26, wherein the data transmission
frames are Ethernet frames.
37. A method according to claim 35, wherein the forwarding control
data contains an IP (Internet Protocol) destination address.
38. A method according to claim 36, wherein the forwarding control
data contains an Ethernet destination address.
39. A method according to claim 26, wherein, on the basis of
forwarding control data for the second data transmission frame,
there is selected one of predefined virtual data transmission
networks.
40. A method according to claim 39, wherein the predefined virtual
data transmission networks are IP VPN (Internet Protocol, Virtual
Private Network) virtual data transmission networks.
41. A method according to claim 39, wherein the predefined virtual
data transmission networks are VPLS (Virtual Private LAN Service)
virtual data transmission networks.
42. A method for controlling the forwarding of data transmission
frames, the method comprising: writing control data into one or
more first data transmission frames, which control data contains
building and cancelling commands for logical data transmission
tunnels determined on the basis of mobility of data terminals
connected to a data transmission network, sending the one or more
first data transmission frames to a data transmission installation
which is part of a ring-shaped data transmission topology, writing
second control data into one or more second data transmission
frames, the second control data containing location-related
information, which is updated on the basis of the mobility of the
data terminals and which enables selecting for the ring-shaped data
transmission topology a data transfer direction which, according to
a predetermined criterion, is more advantageous for carrying a
third data transmission frame, which is addressed to one of the
data terminals, to the commencing point of a logical data
transmission tunnel directed to this particular data terminal, and
sending the one or more second data transmission frames to the data
transmission installation.
43. A computer readable medium storing a computer program including
commands executable by a programmable processor unit for
controlling the programmable processor unit to: read control data
from one or more received first data transmission frames, which
control data contains building and cancelling commands for logical
data transmission tunnels determined on the basis of mobility of
data terminals connected to a data transmission network, execute
building and cancelling actions determined by the control data for
logical data transmission tunnels, determine forwarding actions for
a received second data transmission frame on the basis of
forwarding control data contained in the second data transmission
frame, the forwarding actions comprising a transmission of the
second data transmission frame by way of one of the following
(i-iii): (i) a predetermined output port of a data transmission
installation or (ii) one of two optional predetermined output ports
of the data transmission installation or (iii) a logical data
transmission tunnel commencing from the data transmission
installation.
44. A computer readable medium according to claim 43, wherein the
computer program includes commands executable by a programmable
processor unit for controlling the programmable processor unit so
as to: write the control data into one or more third data
transmission frames to be sent, and write second control data into
one or more fourth data transmission frames to be sent, the second
control data containing location-related information, which is
updated on the basis of the mobility of the data terminals and
which enables selecting for a ring-shaped data transmission
topology a data transfer direction which, according to a
predetermined criterion, is more advantageous for carrying a fifth
data transmission frame, which is addressed to one of the data
terminals, to the commencing point of a logical data transmission
tunnel directed to this particular data terminal.
45. A computer readable medium according to claim 43, wherein the
computer program is stored in a recording medium.
46. A computer readable medium according to claim 43, wherein the
computer program is encoded in a signal which is receivable from a
data transmission network.
47. A system including a first data transmission installation and
second data transmission installations, each of the second data
transmission installations being part of a ring-shaped data
transmission topology and the first data transmission installation
being in data communication with at least one of the second data
transmission installations, wherein the first data transmission
installation includes a processor unit adapted to write control
data into one or more first data transmission frames to be sent,
the control data containing building and cancelling commands for
logical data transmission tunnels determined on the basis of
mobility of data terminals connected to a data transmission
network, and each of the second data transmission installations
includes a processor unit which is adapted to: read the control
data from the one or more first data transmission frames, execute
building and cancelling actions determined by the control data for
logical data transmission tunnels, and determine forwarding actions
for a received second data transmission frame on the basis of
forwarding control data contained in the second data transmission
frame, the forwarding actions comprising one of the following: (i)
a transmission of the second data transmission frame to the
ring-shaped data transmission topology or (ii) a transmission of
the second data transmission frame to a logical data transmission
tunnel commencing from this particular data transmission
installation.
48. A system according to claim 47, wherein the processor unit of
the first data transmission installation is adapted to write second
control data into one or more third data transmission frames to be
sent to the ring-shaped data transmission topology, the second
control data containing location-related information which is
updated on the basis of the mobility of the data terminals, and the
processor unit of each of the second data transmission
installations is adapted to read the control data from the one or
more third data transmission frames, and to select a data transfer
direction in the ring-shaped data transmission topology on the
basis of the second control data and forwarding control data
contained in a data transmission frame to be sent.
49. A system according to claim 47, wherein the processor unit of
each of the second data transmission installations is adapted to
write second control data into one or more third data transmission
frames to be sent to the ring-shaped data transmission topology,
the second control data being adapted to indicate one or more data
terminals with a logical data transmission tunnel directed thereto
commencing from this particular second data transmission
installation, and the processor units of the rest of the second
data transmission installations are adapted to read the second
control data from the one or more third data transmission frames
and to select a data transfer direction in the ring-shaped data
transmission topology on the basis of the second control data and
forwarding control data contained in a data transmission frame to
be sent.
50. A system according to claim 47, wherein the processor unit of
each of the second data transmission installations is adapted to
select a data transfer direction in the ring-shaped data
transmission topology on the basis of forwarding control data
contained in a data transmission frame to be sent and on the basis
of one or more predefined conditions relevant to the forwarding
control data.
51. A system according to claim 48, wherein the processor unit of
each of the second data transmission installations is adapted to
select a data transfer direction in the ring-shaped data
transmission topology primarily on the basis of the second control
data and the forwarding control data and secondarily, in response
to a situation in which the second control data does not fulfill
predetermined criteria, on the basis of the forwarding control data
and one or more predefined conditions relevant to the forwarding
control data.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a data transmission installation
for forwarding data transmission frames. The invention relates also
to a data transmission installation for controlling the forwarding
of data transmission frames. The invention relates also to a method
for forwarding data transmission frames. The invention relates also
to a method for controlling the forwarding of data transmission
frames. The invention relates also to a computer program for
forwarding data transmission frames. The invention relates also to
a system for forwarding data transmission frames.
BACKGROUND OF THE INVENTION
[0002] FIG. 1 shows a system 100 according to the prior art, which
enables linking with mobile telephone network base stations 101,
102 and 103. The system comprises data transmission installations
104, 105, 106 and 107, which can be for example IP (Internet
Protocol) routers, MPLS (Multiprotocol Label Switching) switches
and/or Ethernet switches. Each data transmission installation can
be a single device or a combination of several interconnected
devices. Said data transmission installations are connected to each
other over a local data transmission network 108. The data
transmission network 108 comprises other data transmission
installations and data transmission links therebetween. The system
includes a gateway device 109, providing a link to a data
transmission core network 110, a representative of which can be for
example the global Internet. The gateway device 109 is connected
over the data transmission installation 107 to the local data
transmission network 108. The system 100 is in communication with a
mobility management entity MME 111, which is adapted to maintain an
up-to-date record for the locations of data terminals 112, 113 and
114 in a radio link network established by the base stations 101,
102 and 103. The mobility management entity 111 is connected to the
gateway device 109 either directly or over a data transmission
network. The mobility management entity 111 can also be
incorporated in the gateway device 109. Each of the data terminals
112, 113 and 114 can be for example a mobile telephone or a palm
computer.
[0003] The mobility management entity 111 is adapted, based on the
locations of the data terminals 112, 113 and 114, to establish
control data, on the basis of which the data transmission
installations 104-107 and the gateway device 109 are able to create
logical data transmission tunnels 115, 116 and 117 between the base
stations 101, 102 and 103 and the gateway device 109. Said logical
data transmission tunnels can be for example GTP-U (General Packet
Radio Service Tunneling Protocol--User plane messages) data
transmission tunnels, GRE (Generic Routing Encapsulation) data
transmission tunnels, IPinIP (Internet Protocol in Internet
Protocol) data transmission tunnels or data transmission tunnels
implemented by Ethernet frames.
[0004] In the situation shown in FIG. 1, it is reasonable to
assume, for example, that the data terminal 112 lies within a
coverage range of the base station 101, the data terminal 113 lies
within a coverage range of the base station 102, and the data
terminal 114 lies within a coverage range of the base station 103.
It is further reasonable to assume that the data terminal 112 has
its communications transmitted in the logical data transmission
tunnel 115, the data terminal 113 has its communications
transmitted in the logical data transmission tunnel 116, and the
data terminal 114 has its communications transmitted in the logical
data transmission tunnel 117. In the event that for example the
data terminal 112 passes from the coverage range of the base
station 101 into the coverage range of the base station 102, the
logical data transmission tunnel 115 will be cancelled and a
corresponding new logical data transmission tunnel will be
established between the gateway device 109 and the base station
102. A problem with the above-described type system 100 is that
communications produced by data terminals and communications
addressed thereto proceed by way of the gateway device 109. In
other words, communications produced by data terminals and
communications addressed thereto are forced to proceed by way of a
single point in the data transmission network. As a result, the
local data transmission network 108, the data transmission
installation 107, and the gateway device 109 may be subjected to
heavy loading, which calls for precautionary measures in the
process of designing data transmission links and data transmission
installations.
SUMMARY OF THE INVENTION
[0005] The invention relates to a new type of system, in which the
functionality is decentralized in a data transmission network, such
that there will be less need for communications produced by data
terminals and communications addressed thereto to proceed by way of
a single point in the data transmission network. The system of the
invention comprises: [0006] a first data transmission installation,
and [0007] second data transmission installations, each of which is
part of a ring-shaped data transmission topology and said first
data transmission installation is in data communication with at
least one of said second data transmission installations.
[0008] Said first data transmission installation includes a
processor unit, which is adapted to write control data into one or
more first data transmission frames to be sent to said ring-shaped
data transmission topology, which control data contains building
and cancelling commands for logical data transmission tunnels
determined on the basis of the mobility of data terminals connected
to a data transmission network.
[0009] Each of said second data transmission installations includes
a processor unit, which is adapted to: [0010] read said control
data from said one or more first data transmission frames, [0011]
execute building and cancelling actions determined by said control
data for logical data transmission tunnels, and [0012] determine
forwarding actions for a received second data transmission frame on
the basis of forwarding control data contained in said second data
transmission frame, said forwarding actions comprising one of the
following: (i) a transmission of said second data transmission
frame to said ring-shaped data transmission topology or (ii) a
transmission of said second data transmission frame into a logical
data transmission tunnel commencing from the relevant data
transmission installation.
[0013] Communications produced by said data terminals and
communications addressed thereto need not proceed by way of a
single point in a data transmission network, because said first
data transmission installation is adapted to signal each of said
second data transmission installations to make it capable of
building necessary logical data transmission tunnels, and said
ring-shaped data transmission topology is capable of functioning as
a traffic circle for communications produced by and addressed to
the data terminals. Thus, said logical data transmission tunnels
need not commence or, depending on the direction, terminate at the
same point of a data transmission network as opposed to the prior
art system shown in FIG. 1, in which all logical data transmission
tunnels commence or terminate at the same point of a data
transmission network, i.e. at the gateway device 109.
[0014] Said second data transmission installations need not
necessarily be taught routing or other such information for
enabling a specific second data transmission installation to
control data transmission frames passing to another one of said
second data transmission installations, because said second data
transmission installations constitute part of a ring-shaped data
transmission topology. In a system according to one embodiment of
the invention, said second data transmission installations are
taught the above-mentioned routing and other such information in
order to make said second data transmission installations capable
of selecting an optimal data transmission direction in said
ring-shaped data transmission topology. However, said teaching is
not time-critical.
[0015] The invention relates also to a new type of data
transmission installation for forwarding data transmission frames.
The data transmission installation of the invention encompasses
data receivers for receiving data transmission frames in said data
transmission installation, data transmitters for sending data
transmission frames from said data transmission installation, and a
processor unit which is adapted to: [0016] read control data from
one or more received first data transmission frames, which control
data contains building and cancelling commands for logical data
transmission tunnels determined on the basis of the mobility of
data terminals connected to a data transmission network, [0017]
execute building and cancelling actions determined by said control
data for logical data transmission tunnels, and [0018] determine
forwarding actions for a received second data transmission frame on
the basis of forwarding control data contained in said second data
transmission frame, said forwarding actions comprising a
transmission of said second data transmission frame by way of one
of the following (i-iii): (i) a predetermined output port of said
data transmission installation or (ii) one of two optional
predetermined output ports of said data transmission installation
or (iii) a logical data transmission tunnel commencing from said
data transmission installation.
[0019] Said data transmission installation is preferably used as
part of a ring-shaped data transmission topology. In the event that
said ring-shaped data transmission topology operates on just one
data transfer direction, either clockwise or counter-clockwise, a
data transmission frame to be transmitted to some other
corresponding data transmission installation is always sent by way
of the same predetermined output port. In the event that said
ring-shaped transmission topology operates on both data transfer
directions, a data transmission frame to be transmitted to some
other corresponding data transmission installation is sent by way
of either one of two optional output ports, one output port
corresponding to a clockwise data transfer direction and the other
output port corresponding to a counter-clockwise data transfer
direction.
[0020] The invention relates also to a new type of data
transmission installation for controlling the forwarding of data
transmission frames. The data transmission installation of the
invention comprises data transmitters for sending data transmission
frames from said data transmission installation, and a processor
unit which is adapted to: [0021] write control data into one or
more first data transmission frames to be sent to a second
transmission installation, which control data contains building and
cancelling commands for logical data transmission tunnels
determined on the basis of the mobility of data terminals connected
to a data transmission network, and [0022] write second control
data into one or more second data transmission frames to be sent to
said second data transmission installation, which control data
contains location-related information, which is updated on the
basis of the mobility of said data terminals and which enables
selecting a data transfer direction in the ring-shaped data
transmission topology, which direction, according to a
predetermined criterion, is more favorable for passing a third data
transmission frame, which is addressed to one of said data
terminals, to the commencing point of a logical data transmission
tunnel directed to this particular data terminal.
[0023] The invention relates also to a new type of method for
forwarding data transmission frames, said method comprising: [0024]
receiving one or more first data transmission frames in a data
transmission installation, [0025] reading control data from said
one or more first data transmission frames, which control data
contains building and cancelling commands for logical data
transmission tunnels determined on the basis of the mobility of
data terminals connected to a data transmission network, [0026]
executing building and cancelling actions determined by said
control data for logical data transmission tunnels, [0027]
determining forwarding actions for a received second data
transmission frame on the basis of forwarding control data
contained in said second data transmission frame, said forwarding
actions comprising a transmission of said second data transmission
frame by way of one of the following (i-iii): (i) a predetermined
output port of a data transmission installation or (ii) one of two
optional predetermined output ports of said data transmission
installation or (iii) a logical data transmission tunnel commencing
from said data transmission installation, and [0028] sending said
second data transmission frame in compliance with the determined
forwarding actions.
[0029] The invention relates also to a new type of method for
controlling the forwarding of data transmission frames, said method
comprising: [0030] writing control data into one or more first data
transmission frames, which control data contains building and
cancelling commands for logical data transmission tunnels
determined on the basis of the mobility of data terminals connected
to a data transmission network, [0031] sending said one or more
first data transmission frames to a data transmission installation
which is part of a ring-shaped data transmission topology, [0032]
writing second control data into one or more second data
transmission frames, which control data contains location-related
information, which is updated on the basis of the mobility of said
data terminals and which enables selecting a data transfer
direction in the ring-shaped data transmission topology, which
direction, according to a predetermined criterion, is more
favorable for passing a third data transmission frame, which is
addressed to one of said data terminals, to the commencing point of
a logical data transmission tunnel directed to this particular data
terminal, and [0033] sending said one or more second data
transmission frames to said data transmission installation.
[0034] The invention relates also to a new type of computer program
for forwarding data transmission frames. The computer program of
the invention includes programmatic elements for controlling a
programmable processor unit: [0035] to read control data from one
or more first data transmission frames, which control data contains
building and cancelling commands for logical data transmission
tunnels determined on the basis of the mobility of data terminals
connected to a data transmission network, [0036] to execute
building and cancelling actions determined by said control data for
logical data transmission tunnels, and [0037] to determine
forwarding actions for a received second data transmission frame on
the basis of forwarding control data contained in said second data
transmission frame, said forwarding actions comprising a
transmission of said second data transmission frame by way of one
of the following (i-iii): (i) a predetermined output port of a data
transmission installation or (ii) one of two optional predetermined
output ports of said data transmission installation or (iii) a
logical data transmission tunnel commencing from said data
transmission installation.
[0038] The various embodiments of the invention are characterized
by what is presented in the dependent claims.
BRIEF DESCRIPTION OF THE FIGURES
[0039] The following description deals with embodiments and
benefits of the invention in more detail with reference to the
exemplary embodiments and accompanying drawings, in which
[0040] FIG. 1 shows a system according to the prior art for
forwarding data transmission frames,
[0041] FIGS. 2a and 2b show systems according to certain
embodiments of the invention for forwarding data transmission
frames,
[0042] FIG. 3 shows a data transmission installation according to
one embodiment of the invention for forwarding data transmission
frames,
[0043] FIG. 4 shows a data transmission installation according to
one embodiment of the invention for controlling the forwarding of
data transmission frames,
[0044] FIG. 5 shows in a flow chart a method according to one
embodiment of the invention for forwarding data transmission
frames,
[0045] FIG. 6 shows in a flow chart a method according to one
embodiment of the invention for controlling the forwarding of data
transmission frames.
[0046] FIG. 1 has been described earlier in this document in
connection with the description of the prior art.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0047] FIG. 2a shows a system 200 according to one embodiment of
the invention, which enables linking with mobile telephone network
base stations 201, 202 and 203. The system comprises a first data
transmission installation 207 and second data transmission
installations 204, 205 and 206. Said data transmission
installations can be for example IP (Internet Protocol) routers,
MPLS (Multiprotocol Label Switching) switches, and/or Ethernet
switches. Each data transmission installation can be a single
device or a combination of several interconnected devices. The data
transmission installations 204, 205 and 206 make up a ring-shaped
data transmission topology. The data transmission installation 207
is in data communication with at least one of said data
transmission installations 204, 205 and 206. The system 200 is
connected by way of the data transmission installation 207, or by
way of some other data transmission installation which is in
communication with the data transmission installation 207, to a
data transmission core network 210, a representative of which can
be for example the global Internet. The system 200 is in
communication with a mobility management entity MME 211, which is
adapted to maintain an up-to-date record for the locations of data
terminals 212, 213 and 214 in a radio link network established by
the base stations 201, 202 and 203. Each data terminal can be for
example a mobile telephone or a palm computer. The mobility
management entity 211 is connected to the data transmission
installation 207 either directly or by way of some other data
transmission installation. It is also possible that the mobility
management entity 211 is incorporated in the data transmission
installation 207.
[0048] The mobility management entity 211 is adapted, based on
locations of the data terminals 212, 213 and 214, to establish
control data on the basis of which logical data transmission
tunnels 215, 216 and 217 can be created between the base stations
201, 202 and 203 and the data transmission installations 204, 205
and 206. Said logical data transmission tunnels can be for example
GTP-U (General Packet Radio Service Tunneling Protocol--User plane
messages) data transmission tunnels, GRE (Generic Routing
Encapsulation) data transmission tunnels, IPinIP (Internet Protocol
in Internet Protocol) data transmission tunnels, or data
transmission tunnels implemented by Ethernet frames. Said logical
data transmission tunnels comprise preferably both a downstream
tunnel from the data transmission installation to the base station
and an upstream tunnel from the base station to the data
transmission installation. The GRE data transmission tunnel has
been described for example in technical specification IETF RFC2784
(Internet Engineering Task Force--Request for Comments). The IPinIP
data transmission tunnel has been described for example in
technical specification IETF RFC2003, and the GTP-U data
transmission tunnel has been described for example in technical
specification 3GPP TS29.060 (3.sup.rd Generation Partnership
Project, Technical Specification).
[0049] Data transmission between the data transmission
installations 204, 205, 206, and 207 as well as the base stations
201, 202 and 203 can be implemented by using for example one or
more of the following data transfer protocols: [0050] IP (Internet
Protocol), the addresses used therein being selectable for example
from the public IP address space, [0051] Ethernet, [0052] IP VPN
(Internet Protocol, Virtual Private Network), and/or [0053] VPLS
(Virtual Private LAN Service, LAN=Local Area Network).
[0054] The IP VPN and VPLS protocols enable defining parallel
virtual data transmission networks in the system 200. For example,
data transmission frames produced by and addressed to the data
terminals of corporate subscribers can be carried by a virtual data
transmission network A and data transmission frames produced by and
addressed to the data terminals of private subscribers can be
carried by another virtual data transmission network B. It is also
possible to use separate virtual transmission networks for data
transmission frames produced by and addressed to the data terminals
of various subscribers according to charges paid by said
subscribers. IP VPN has been described for example in technical
specification IETF RFC4364 and VPLS has been described for example
in technical specification IETF RFC4762.
[0055] Data transmission between the data transmission
installations 204, 205, 206 and 207 as well as the base stations
201, 202 and 203 can also be implemented by using logical data
transmission tunnels such as GTP-U (General Packet Radio
Service--User plane messages) data transmission tunnels, GRE
(Generic Routing Encapsulation) data transmission tunnels, IPinIP
(Internet Protocol in Internet Protocol) data transmission tunnels,
and/or data transmission tunnels established by Ethernet
frames.
[0056] The data transmission installation 207 comprises data
transmitters for sending data transmission frames to a ring-shaped
data transmission topology established by the data transmission
installations 204, 205 and 206. The data transmission frames can be
for example IPv4 packets, IPv6 (Internet Protocol) packets, or
Ethernet frames. The data transmission installation 207 includes a
processor unit, which is adapted to write control data CD into one
or more first transmission frames F1 to be sent, which control data
contains building and cancelling commands for the logical data
transmission tunnels 215, 216 and 217, determined on the basis of
mobility of the data terminals 212, 213 and 214. Said control data
CD is based on information received by the data transmission
installation 207 from the mobility management entity 211.
[0057] Each of the data transmission installations 204, 205 and 206
includes data receivers for receiving data transmission frames, and
data transmitters for sending data transmission frames. Each of the
data transmission installations 204, 205 and 206 is provided with a
processor unit, which is adapted to: [0058] read said control data
CD from said one or more received first data transmission frames
F1, [0059] execute building and cancelling actions determined by
said control data for logical data transmission tunnels, and [0060]
determine forwarding actions for a received second data
transmission frame F2 on the basis of forwarding control data
contained in said second data transmission frame, said forwarding
actions comprising one of the following: (i) a transmission of said
second data transmission frame to a ring-shaped data transmission
topology established by the data transmission devices 204, 205 and
206 or (ii) a transmission of said second data transmission frame
into a logical data transmission tunnel commencing from the
relevant data transmission installation.
[0061] The above-mentioned data transmission frames F1 and F2 can
be for example IP (Internet Protocol) packets or Ethernet frames.
The IP packets can be either IPv4 or IPv6 packets (Internet
Protocol--version 4, Internet Protocol--version 6).
[0062] The forwarding control data contained in a data transmission
frame can be for example an IP destination address or an Ethernet
destination address. In addition, the forwarding control data may
contain a piece of information indicating a CoS (Class of Service)
applicable to a data transmission frame, or a piece of information
indicating a virtual data transmission network used for a data
transmission frame.
[0063] In the situation shown in FIG. 2a, it is reasonable to
assume, for example, that the data terminal 212 lies within a
coverage range of the base station 201, the data terminal 213 lies
within a coverage range of the base station 202, and the data
terminal 214 lies within a coverage range of the base station 203.
It is further presumed that the data terminal 212 produces a data
transmission frame addressed to the data terminal 213. Thus, the
data transmission installation 204 receives said data transmission
frame from the logical data transmission tunnel 215 and sends said
data transmission frame to a ring-shaped data transmission topology
established by the data transmission devices 204, 205 and 206. Said
data transmission frame ends up in the data transmission
installation 205 either directly or by way of the data transmission
installation 206, depending on which data transfer direction the
data transmission installation 204 is adapted to choose for sending
said data transmission frame. On the basis of said control data CD
and said data transmission frame forwarding control data, the data
transmission installation 205 is adapted to notice that said data
transmission frame is addressed to such a data terminal, which has
a logical data transmission tunnel directed thereto commencing from
this particular data transmission installation 205. Thereafter, the
data transmission installation 205 sends said data transmission
frame in the logical data transmission tunnel 216 to the base
station 202 and to be forwarded from there to the data terminal
213. In other words, the data transmission installation 205 sends
said data transmission frame into the logical data transmission
tunnel 216, which provides access to the data terminal 213. The
forwarding control data included in the data transmission frame may
contain for example an IP destination address.
[0064] Communications produced by the data terminals 212, 213 and
214 and communications addressed thereto need not pass by way of a
single point in a data transmission network, because the data
transmission installation 207 is adapted to signal each of the data
transmission installations 204, 205 and 206 to make it capable of
creating necessary logical data transmission tunnels, and the
ring-shaped data transmission topology established by the data
transmission installations 204, 205 and 206 is capable of
functioning as a traffic circle for communications produced by and
addressed to the data terminals 212, 213 and 214. As a result, the
logical data transmission tunnels need not commence, or depending
on the direction, need not terminate at the same point of a data
transmission network as opposed to the prior art system shown in
FIG. 1, in which all logical data transmission tunnels commence or
terminate at the same point of a data transmission network, i.e. at
the gateway device 109. The data transmission installations 204,
205 and 206 need not necessarily be taught routing and other such
information in order to enable each of these data transmission
installations 204, 205 and 206 to send data transmission frames to
be delivered to any other of said data transmission installations
204, 205 and 206, because said data transmission installations 204,
205 and 206 make up a ring-shaped data transmission topology.
[0065] In a system according to one embodiment of the invention,
one or more of the data transmission installations 204, 205 and 206
is/are taught routing or other relevant information for making said
data transmission installations capable of selecting an optimal
data transfer direction in a ring-shaped data transmission topology
established by the data transmission installations 204, 205 and
206. However, the discussed teaching is not time-critical.
[0066] In a system according to one embodiment of the invention,
the data transmission installation 207 has its processor unit
adapted to write second control data CD2 into one or more data
transmission frames, which is/are sent to a ring-shaped data
transmission topology established by the data transmission
installations 204, 205 and 206. Said second control data CD2
contains location-related information updated on the basis of the
mobility of the data terminals 212, 213 and 214. Each of the data
transmission installations 204, 205 and 206 has its processor unit
adapted to read said second control data CD2 from said one or more
data transmission frames and to select a data transfer direction in
said ring-shaped data transmission topology on the basis of said
second control data CD2 and the forwarding control data contained
in a data transmission frame to be sent. Accordingly, each of the
data transmission installations 204, 205 and 206 is capable of
choosing an optimal data transfer direction, which can be clockwise
or counter-clockwise, in said ring-shaped data transmission
topology. In the above-presented example, in which the data
terminal 212 sends a data transmission frame addressed to the data
terminal 213, the data transmission installation 204 is able to
send said data transmission frame directly to the data transmission
installation 205 on the basis of said second control data CD2 and
the forwarding control data contained in said data transmission
frame. Said second control data CD2 may contain for example an IP
or Ethernet forwarding table or updates for one or both of said
forwarding tables, which enables/enable the determination of an
optimal data transfer direction in said ring-shaped data
transmission topology, for example on the basis of an IP or
Ethernet destination address, DA.
[0067] In a system according to one embodiment of the invention,
each of the data transmission installations 204, 205 and 206 has
its processor unit adapted to write control data into one or more
data transmission frames to be sent to said ring-shaped data
transmission topology, which control data is adapted to indicate
one or more data terminals with a logical data transmission tunnel
directed thereto commencing from the relevant data transmission
installation 204, 205 or 206. Each of the data transmission
installations 204, 205 and 206 has its processor unit adapted to
read said control data from one or more data transmission frames
and to choose a data transfer direction in said ring-shaped data
transmission topology on the basis of said control data and the
forwarding control data contained in a data transmission frame to
be sent. Thereby, each of the data transmission installations 204,
205 and 206 is capable of selecting an optimal data transfer
direction, which can be clockwise or counter-clockwise, in said
ring-shaped data transmission topology.
[0068] In a system according to one embodiment of the invention,
each of the data transmission installations 204, 205 and 206 has
its processor unit adapted to select a data transfer direction on
the basis of the forwarding control data contained in a data
transmission frame to be transmitted in said ring-shaped data
transmission topology, and on the basis of one or more
predetermined conditions relevant to said forwarding control data.
Said predetermined condition may, for example, disclose the data
transfer direction on the basis of knowing which data terminal a
data transmission frame to be sent is addressed to. Said
predetermined condition may have been created for example on the
basis of which base station's coverage range is the most likely
location for a given data terminal. In the event that for example
the data terminal 213 is most likely located within a coverage
range of the base station 202, said predetermined condition in the
data transmission installation 204 can be as follows: the data
transfer direction is counter-clockwise in case the data
transmission frame is addressed to the data terminal 213. In the
data transmission installation 206, respectively, the predetermined
condition can be as follows: the data transfer direction is
clockwise in case the data transmission frame is addressed to the
data terminal 213. The predetermined conditions applied in one or
more data transmission installations 204, 205 and 206 may also be
time-dependent, in case it is known, for example, that, during a
specific time period, a specific data terminal is most likely
located within the coverage range of a specific base station and,
during some other time period, within the coverage range of some
other base station.
[0069] In a system according to one embodiment of the invention,
each of the data transmission installations 204, 205 and 206 has
its processor unit adapted to choose a data transfer direction in
said ring-shaped data transmission topology primarily on the basis
of control data, which has been updated on the basis of the
mobility of data terminals, and on the basis of forwarding control
data for a data transmission frame to be sent, and secondarily on
the basis of said forwarding control data and one or more
predetermined conditions relevant to said forwarding control data.
Therefore, in the situation that said control data does not exist,
or it is irrelevant because said control data is outdated, the data
transfer direction can be chosen for example on the basis of which
base station's coverage range is the most likely location for this
particular data terminal.
[0070] FIG. 2b shows a system 200 according to one embodiment of
the invention, which enables linking with mobile phone network base
stations 201, 202 and 203. The system shown in FIG. 2b is otherwise
similar to that shown in FIG. 2a except that the ring-shaped data
transmission topology comprises also data transmission
installations 209 and 207 other than just those data transmission
installations 204, 205 and 206 providing access to the base
stations 201, 202 and 203.
[0071] In the systems 200 shown in FIGS. 2a and 2b, the data
transmission installations 204 and 206 are connected by way of data
transmission links directly to the base stations 201 and 203, and
the data transmission installation 205 is connected to the base
station 202 by way of a data transmission installation 218. The
data transmission installation 218 is preferably adapted to forward
data transmission frames to be carried in a logical data
transmission tunnel 216 without terminating said logical data
transmission tunnel.
[0072] FIG. 3 shows a data transmission installation 320 according
to one embodiment of the invention for forwarding data transmission
frames. The data transmission installation can be for example an IP
(Internet Protocol) router, an MPLS (Multiprotocol Label Switching)
switch, and/or an Ethernet switch. The data transmission
installation includes data receivers 321 and 326 for receiving data
transmission frames from a data transmission network 308, and data
transmitters 322 and 327 for sending data transmission frames to
said data transmission network. The data transmission frames can be
for example IPv4 packets, IPv6 packets (IP=Internet Protocol), or
Ethernet frames.
[0073] The data transmission installation includes a processor unit
323, which is adapted to: [0074] read control data CD from one or
more first data transmission frames received from said data
transmission network, which control data contains building and
cancelling commands for logical data transmission tunnels
determined on the basis of the mobility of data terminals connected
to said data transmission network, [0075] execute building and
cancelling actions determined by said control data CD for logical
data transmission tunnels, and [0076] determine forwarding actions
for a received second data transmission frame on the basis of
forwarding control data contained in said second data transmission
frame, said forwarding actions comprising a transmission of said
second data transmission frame to said data transmission network by
way of one of the following (i-iii): (i) a predetermined output
port of said data transmission installation or (ii) one of two
optional predetermined output ports of said data transmission
installation or (iii) a logical data transmission tunnel commencing
from said data transmission installation.
[0077] The data transmission installation may also include a data
storage 324 and/or a connecting interface 325 for linking with an
external data storage. The processor unit 323 may consist of one or
several processors, each of which can be for example a programmable
processor, an application specific integrated circuit ASIC, a field
programmable gate array FPGA, or a combination of one or more of
the above.
[0078] The data transmission installation 320 is preferably used as
part of a ring-shaped data transmission topology. The data
transmission installation 320 can be for example any of the data
transmission installations 204, 205 and 206 shown in FIGS. 2a and
2b. In the event that said ring-shaped data transmission topology
only operates on a single data transfer direction, either clockwise
or counter-clockwise, a data transmission frame to be sent to some
other corresponding data transmission installation will be
transmitted by way of a specific predetermined output port. Said
predetermined output port can be implemented for example by means
of the data transmitters 322. In the event that said ring-shaped
data transmission topology operates on both data transfer
directions, a data transmission frame to be sent to some other
corresponding data transmission installation will be transmitted by
way of either one of two optional output ports, one output port
corresponding to a clockwise data transfer direction and the other
output port corresponding to a counter-clockwise data transfer
direction. One of said two optional predetermined output ports can
be implemented by means of the data transmitters 322 and the other
of said two optional predetermined output ports can be implemented
by means of the data transmitters 327.
[0079] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
read second control data CD2 from one or more data transmission
frames received from said data transmission network, and to select
one of said two optional predetermined output ports on the basis of
said second control data CD2 and the forwarding control data
contained in a data transmission frame to be sent. Thereby, the
data transmission installation 320 is capable of choosing an
optimal data transfer direction, which can be clockwise or
counter-clockwise in said ring-shaped data transmission topology.
Said second control data CD2 may contain for example an IP or
Ethernet forwarding table or updates for one or both of said
forwarding tables (IP forwarding table, Ethernet forwarding table),
which enables/enable determining an optimal data transfer direction
in said ring-shaped data transmission topology for example on the
basis of an IP or Ethernet destination address DA.
[0080] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
select one of said two optional predetermined output ports on the
basis of forwarding control data contained in a data transmission
frame to be sent and on the basis of one or more predetermined
conditions regarding said forwarding control data. Said
predetermined condition can be created for example on the basis of
which base station's coverage range is the most likely location for
a specific data terminal.
[0081] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
read second control data CD2 from one or more data transmission
frames received from said data transmission network, and to
primarily choose one of said two optional predetermined output
ports on the basis of said second control data CD2 and the
forwarding control data contained in a data transmission frame to
be sent, and to secondarily choose the other of said two optional
predetermined output ports on the basis of said forwarding control
data and one or more predetermined conditions relevant to said
forwarding control data. Thus, in the situation in which said
second control data CD2 does not exist, or it is irrelevant because
said second control data CD2 is outdated, the data transfer
direction can be chosen for example on the basis of which base
station's coverage range is the most likely location for this
particular data terminal.
[0082] In the data transmission installation 320 according to one
embodiment of the invention, the processor unit 323 is adapted to
write control data into one or more data transmission frames to be
sent to said data transmission network 308, which control data is
adapted to indicate one or more data terminals with a logical data
transmission tunnel directed thereto commencing from the discussed
data transmission installation 320. A second corresponding data
transmission installation, present in said ring-shaped data
transmission topology, is capable of selecting an optimal data
transfer direction on the basis of said control data and the
forwarding control data for a data transmission frame to be
sent.
[0083] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
support GTP-U data transmission tunnels. In this case, said data
transmission tunnels are preferably GTP-U (General Packet Radio
Service Tunneling Protocol--User plane messages) data transmission
tunnels.
[0084] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
support GRE data transmission tunnels. In this case, said data
transmission tunnels are preferably GRE (Generic Routing
Encapsulation) data transmission tunnels.
[0085] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
support data transmission tunnels implemented by means of Ethernet
frames. In this case, said data transmission tunnels are preferably
implemented by means of Ethernet frames.
[0086] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
support IPinIP data transmission tunnels. In this case, said data
transmission tunnels are preferably IPinIP (Internet Protocol in
Internet Protocol) data transmission tunnels.
[0087] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
use an IP destination address, contained in an IP (Internet
Protocol) packet, at least as a part of the forwarding control data
relevant to said IP packet.
[0088] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
use an Ethernet destination address, contained in an Ethernet
frame, at least as a part of the forwarding control data relevant
to said Ethernet frame.
[0089] In a data transmission installation according to one
embodiment of the invention, the processor unit 323 is adapted to
select, on the basis of data transmission frame forwarding control
data, one of the virtual data transmission networks predefined in
the data transmission network 308. Each virtual data transmission
network can be for example an IP VPN (Internet Protocol, Virtual
Private Network) virtual data transmission network or a VPLS
(Virtual Private LAN Service) virtual data transmission
network.
[0090] FIG. 4 shows a data transmission installation 420 according
to one embodiment of the invention for forwarding data transmission
frames. The data transmission installation may function for example
as the data transmission installation 207 shown in FIGS. 2a and 2b.
The data transmission installation can be for example an IP
(Internet Protocol) router, an MPLS (Multiprotocol Label Switching)
switch, and/or an Ethernet switch. The data transmission
installation includes data transmitters 422 and 427 for sending
data transmission frames to a data transmission network 408. The
data transmission frames can be for example IPv4 packets, IPv6
(Internet Protocol) packets or Ethernet frames. The data
transmission installation is provided with a processor unit 423,
which is adapted to: [0091] write control data into one or more
first data transmission frames to be sent to another data
transmission installation, which control data contains building and
cancelling commands for logical data transmission tunnels
determined on the basis of the mobility of data terminals connected
to the data transmission network 408, and [0092] write second
control data into one or more second data transmission frames to be
sent to said other data transmission installation, which control
data contains location-related information updated on the basis of
the mobility of said data terminals.
[0093] Said second control data enables selecting for a ring-shaped
data transmission topology a data transfer direction which,
according to a predetermined criterion, is preferred for carrying
such a data transmission frame, which is addressed to one of said
data terminals, to the commencing point of a logical data
transmission tunnel directed to the discussed data terminal.
[0094] Said logical data transmission tunnels can be for example
GTP-U (General Packet Radio Service Tunneling Protocol--User plane
messages) data transmission tunnels, GRE (Generic Routing
Encapsulation) data transmission tunnels, IPinIP (Internet Protocol
in Internet Protocol) data transmission tunnels, or data
transmission tunnels implemented by means of Ethernet frames.
[0095] The data transmission installation may also include a data
storage 424 and/or a connecting interface 425 for linking with an
external data storage. The processor unit 423 may consist of one or
several processors, each of which can be for example a programmable
processor, an application specific integrated circuit ASIC, a field
programmable gate array FPGA, or a combination of one or more of
the above.
[0096] The data transmission installation 420 according to one
embodiment of the invention comprises data receivers 421 and 426
for receiving data transmission frames from said data transmission
network. The processor unit 423 is adapted to read said data
transmission frames for building and cancelling commands regarding
said logical data transmission tunnels. Said data transmission
frames may contain information transmitted by a mobility management
entity (211, FIGS. 2a and 2b).
[0097] The data transmission installation 420 according to one
embodiment of the invention includes a connecting interface 425,
which enables linking the data transmission installation to the
mobility management entity.
[0098] FIG. 5 shows in a flow chart a method according to one
embodiment of the invention for forwarding data transmission
frames. Step 501 comprises receiving one or more first data
transmission frames F1 in a data transmission installation from a
data transmission network. Step 502 comprises reading control data
CD from said one or more first data transmission frames F1, which
control data contains building and cancelling commands for logical
data transmission tunnels determined on the basis of the mobility
of data terminals connected to said data transmission network. Step
503 comprises executing building and cancelling actions determined
by said control data for logical data transmission tunnels. Step
504 comprises determining forwarding actions for a received second
data transmission frame F2 on the basis of forwarding control data
contained in said second data transmission frame F2. Said
forwarding actions comprise a transmission of said second data
transmission frame F2 to said data transmission network by way of
one of the following (i-iii): (i) a predetermined output port of
said data transmission installation or (ii) one of two optional
predetermined output ports of said data transmission installation
or (iii) a logical data transmission tunnel commencing from said
data transmission installation. Step 505 comprises sending said
second data transmission frame F2 to said data transmission network
in compliance with the determined forwarding actions.
[0099] A method according to one embodiment of the invention
comprises reading one or more third data transmission frames F3,
received from said data transmission network, for second control
data CD2 and selecting one of said two optional output ports on the
basis of said second control data and the forwarding control data
contained in said second data transmission frame F2.
[0100] A method according to one embodiment of the invention
comprises selecting one of said two optional predetermined output
ports on the basis of forwarding control data contained in said
second data transmission frame F2 and one or more predefined
conditions relevant to said forwarding control data.
[0101] A method according to one embodiment of the invention
comprises reading second control data CD2 from one or more third
data transmission frames F3 received from said data transmission
network and primarily selecting one of said two optional
predetermined output ports on the basis of said second control data
CD2 and forwarding control data contained in said second data
transmission frame F2, and secondarily selecting one of said two
optional predetermined output ports on the basis of forwarding
control data contained in said second data transmission frame F2
and one or more predefined conditions relevant to said forwarding
control data.
[0102] A method according to one embodiment of the invention
comprises writing third control data CD3 into one or more fourth
data transmission frames F4 to be sent to said data transmission
network, which control data is adapted to indicate one or more data
terminals with a logical data transmission tunnel directed thereto
commencing from said data transmission installation.
[0103] Said data transmission frames can be for example IPv4, IPv6
(Internet Protocol) packets or Ethernet frames. Said logical data
transmission tunnels can be for example GTP-U (General Packet Radio
Service Tunneling Protocol--User plane messages) data transmission
tunnels, GRE (Generic Routing Encapsulation) data transmission
tunnels, IPinIP (Internet Protocol in Internet Protocol) data
transmission tunnels, or data transmission tunnels implemented by
means of Ethernet frames. Said forwarding control data may contain
for example an IP (Internet Protocol) destination address or an
Ethernet destination address.
[0104] A method according to one embodiment of the invention
comprises selecting, on the basis of forwarding control data for
said second data transmission frame F2, one of the virtual data
transmission networks predefined in said data transmission network.
Each of said virtual data transmission networks can be for example
an IP VPN (Internet Protocol, Virtual Private Network) virtual data
transmission network or a VPLS (Virtual Private LAN Service)
virtual data transmission network.
[0105] The method shown in FIG. 5 can be executed for example in
the data transmission installation 204, the data transmission
installation 205 and/or the data transmission installation 206 of
the system illustrated in FIGS. 2a and 2b.
[0106] FIG. 6 shows in a flow chart a method according to one
embodiment of the invention for controlling the forwarding of data
transmission frames. Step 601 comprises writing control data CD
into one or more first data transmission frames F1, which control
data contains building and cancelling commands for logical data
transmission tunnels determined on the basis of the mobility of
data terminals connected to a data transmission network. Step 602
comprises sending said one or more first data transmission frames
F1 by way of said data transmission network to a data transmission
installation T included in a ring-shaped data transmission
topology. Step 603 comprises writing second control data CD2 into
one or more second data transmission frames F2, which control data
contains location-related information updated on the basis of the
mobility of said data terminals. Said second control data CD2
enables selecting a data transfer direction for said ring-shaped
data transmission topology, which direction, according to a
predetermined criterion, is preferred for carrying such a data
transmission frame, which is addressed to one of said data
terminals, to the commencing point of a logical data transmission
tunnel directed to this particular data terminal. Step 604
comprises sending said one or more data transmission frames F2 by
way of said data transmission network to said data transmission
installation T.
[0107] Said data transmission frames can be for example IPv4, IPv6
(Internet Protocol) packets or Ethernet frames. Said logical data
transmission tunnels can be for example GTP-U (General Packet Radio
Service Tunneling Protocol--User plane messages) data transmission
tunnels, GRE (Generic Routing Encapsulation) data transmission
tunnels, IPinIP (Internet Protocol in Internet Protocol) data
transmission tunnels, or data transmission tunnels implemented by
means of Ethernet frames.
[0108] The method shown in FIG. 6 can be executed for example in
the data transmission installation 207 included in the system shown
in FIGS. 2a and 2b. In this case, said control data CD and said
second control data CD2 are preferably transmitted to the data
transmission installations 204, 205 and 206. It is also possible
that each of the data transmission installations 204, 205 and 206
be only supplied with appropriate portions of said control data CD
and said second control data CD2.
[0109] The computer program according to one embodiment of the
invention for forwarding data transmission frames contains commands
executable by a programmable processor unit for controlling said
programmable processor unit so as to: [0110] read control data from
one or more first data transmission frames received from a data
transmission network, which control data contains building and
cancelling commands for logical data transmission tunnels
determined on the basis of the mobility of data terminals connected
to a data transmission network, [0111] execute building and
cancelling actions determined by said control data for logical data
transmission tunnels, and [0112] determine forwarding actions for a
received second data transmission frame on the basis of forwarding
control data contained in said second data transmission frame, said
forwarding actions comprising a transmission of said second data
transmission frame by way of one of the following (i-iii): (i) a
predetermined output port of a data transmission installation or
(ii) one of two optional predetermined output ports of said data
transmission installation or (iii) a logical data transmission
tunnel commencing from said data transmission installation.
[0113] The foregoing computer program can be used for example in
the data transmission installation 204, the data transmission
installation 205 and/or the data transmission installation 206
included in the system shown in FIGS. 2a and 2b.
[0114] The computer program according to one embodiment of the
invention for controlling the forwarding of data transmission
frames contains commands executable by a programmable processor
unit for controlling said programmable processor unit so as to:
[0115] write control data into one or more first data transmission
frames to be sent to a data transmission installation, which
control data contains building and cancelling commands for logical
data transmission tunnels determined on the basis of the mobility
of data terminals connected to a data transmission network, and
[0116] write second control data into one or more second data
transmission frames to be sent to said data transmission
installation, which control data contains location-related
information updated on the basis of the mobility of said data
terminals.
[0117] Said second control data enables selecting for a ring-shaped
data transmission topology a data transfer direction which,
according to a predetermined criterion, is preferred for carrying
such a data transmission frame, which is addressed to one of said
data terminals, to the commencing point of a logical data
transmission tunnel directed to this particular data terminal.
[0118] The foregoing computer program can be used for example in
the data transmission installation 207 included in the system shown
in FIGS. 2a and 2b. In this case, said control data and said second
control data are preferably transmitted to the data transmission
installations 204, 205 and 206. It is also possible that each of
the data transmission installations 204, 205 and 206 be only
supplied with such portions of said control data and second control
data which are appropriate for this particular data transmission
installation.
[0119] The computer program according to one embodiment of the
invention contains commands as described above, executable by a
programmable processor unit, both for forwarding data transmission
frames and for controlling the forwarding of data transmission
frames. The computer program according to this embodiment of the
invention can be used in the data transmission installations 204,
205, 206 and 207 included in the system shown in FIGS. 2a and
2b.
[0120] The computer program according to one embodiment of the
invention is stored in a recording medium, such as for example in
an optical disk (Compact Disk, CD), readable by a programmable
processor unit.
[0121] A computer program according to one embodiment of the
invention is encoded into a signal which is receivable from a data
transmission network such as, for example, the Internet.
[0122] As obvious for a skilled artisan, the invention and its
embodiments are not limited to the foregoing exemplary
implementations. The expressions included in the claims for the
presence of characterizing features, for example "the data
transmission installation includes a processor unit" are open in
the sense that the presentation of characterizing features does not
exclude the presence of other such features that have not been
presented in the independent or dependent claims.
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